Recently, the Joint Commission added exclusive breastfeeding as a perinatal care core measure to assess maternity center quality. Both the Joint Commission and the American Academy of Pediatrics identified supporting breastfeeding women as an important quality of care concern for hospitals in the United States. The proposed study examines the individually attributable marginal effect of exposure to policies reflecting each one of the Ten Steps to Successful Breastfeeding on exclusive breastfeeding at hospital discharge, exclusive breastfeeding duration, and any breastfeeding duration. The findings from this study will aid hospital policy makers in prioritizing Step implementation as they seek to increase exclusive breastfeeding in response to the new Joint Commission measure. Ultimately, the findings from this study will result in improved quality of care by providing information that will support women with their feeding intentions. PUBLIC HEALTH RELEVANCE: The proposed study will identify the individual impact of each of the Ten Steps to Successful Breastfeeding on exclusive breastfeeding at hospital discharge (the new Joint Commission perinatal care core measure), exclusive breastfeeding duration, and any breastfeeding duration. This study will provide hospital administrators that may not want to implement all Ten Steps, information to guide the prioritization of Step implementation as they seek to make incremental steps towards supporting women in their infant feeding decisions.